Hepatocyte growth factor up-regulates SGLT1 and GLUT5 gene expression after massive small bowel resection.
OBJECTIVE
Hepatocyte growth factor (HGF), originally known to stimulate hepatocyte DNA synthesis, also has been shown to stimulate growth of intestinal epithelial cells in vitro. The authors recently demonstrated that HGF can dramatically increase substrate absorption beyond the normal adaptive response after massive small bowel resection in the rat. However, the mechanism for this enhanced substrate absorption is unknown. This study was designed to determine if up-regulation of gene expression by HGF of the Na+/glucose cotransporter SGLT1 and the facilitative glucose transporter GLUT5 is a possible mechanism of action.


METHODS
Young adult Sprague-Dawley rats underwent an 80% small bowel resection and jejunostomy tube placement. Seven days later, an osmotic minipump was connected to the subcutaneously placed jejunostomy tube. The rats were divided into two groups based on the contents in the minipumps: group 1, saline (control, n = 5); and group 2, HGF at 75 microg/kg/d (n = 5). After a 14-day infusion, biopsy specimens of the small bowel mucosa were obtained. After total RNA extraction, Northern blot analysis was performed with SGLT1 and GLUT5 cDNA probes. Auto radiographs were quantitated by image analysis.


RESULTS
SGLT1 mRNA levels were significantly up-regulated in the HGF-treated animals (121% increase, P<.01) when compared with the control. Up-regulation of GLUT5 mRNA levels was also seen in the HGF-treated animals (96% increase, P < .01).


CONCLUSIONS
These data, demonstrating that HGF upregulates intestine epithelial glucose transporter gene expression after massive small bowel resection, may elucidate a mechanism of action for the enhanced carbohydrate absorption after HGF administration. This growth factor may be useful for patients with short bowel syndrome.
Kato
Y
Y
Dupont Hospital for Children, Wilmington, DE 19899, USA.
Yu
D
D
Schwartz
M Z
MZ
D000818:Animals; D015152:Blotting, Northern; D015870:Gene Expression; D005947:Glucose / Q000378:metabolism; D051296:Glucose Transporter Type 5; D017228:Hepatocyte Growth Factor / Q000494:pharmacology*; D007421:Intestine, Small / Q000601:surgery*; D007441:Intubation, Gastrointestinal; D007582:Jejunostomy; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D009004:Monosaccharide Transport Proteins / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D012778:Short Bowel Syndrome / Q000188:drug therapy; D012964:Sodium / Q000378:metabolism; D051269:Sodium-Glucose Transporter 1; D015854:Up-Regulation
D051296:Glucose Transporter Type 5; D008562:Membrane Glycoproteins; D009004:Monosaccharide Transport Proteins; D012333:RNA, Messenger; C495676:Slc5a1 protein, rat; D051269:Sodium-Glucose Transporter 1; D017228:Hepatocyte Growth Factor; D012964:Sodium; D005947:Glucose